Best building energy management systems (BEMS)
The best BEMS software measures energy at the meter, compares it with a weather-normalized expected value and acts on the equipment behind the gap. Most BMS vendors now add energy suites to their controls. Aqueduct starts from metering and baselines and adds control over open protocols.
BMS, BEMS and EMS
BMS
Runs heating, cooling, ventilation and lighting to a programmed schedule, and reports whether plant did what it was told.
BEMS
Adds metering and energy reports to those controls, so a team sees what each system consumed as well as how it ran.
EMS
Reads utility meters, sub-meters and bills to report use and cost by site, usually without switching any plant.
BMS vs BEMS vs EMS
Where each term comes from, why the line is blurring and how to decide which one a site needs.
Learn moreWhat a BEMS should prove
Sub-metered use
Energy by feeder, system and floor, not only the main incomer.
Weather normalization
Expected use from degree days, so a hot month does not hide a fault.
Cost at your tariff
The gap priced in money, split into usage and rate.
Action and check
A control change on the equipment, then the meter confirming it held.
BEMS options compared
Energy functions as each vendor describes them on its own page, linked in the sources.
| System | Energy functions the vendor names | Baseline method | Equipment control |
|---|---|---|---|
| Siemens Desigo CC | Electrical and utility meters via open protocols, energy and power reports, virtual meters, power quality. | Not described on the product page. | Central hub for HVAC, lighting, fire safety and security. |
| Johnson Controls Metasys | Energy management suite for emissions tracking, benchmarking and budgeting. | Not described on the product page. | Open building automation system. |
| Honeywell Forge Performance+ | Cloud software that continuously optimizes HVAC operation with AI and machine learning. | Not described on the product page. | Automated HVAC optimization. |
| Schneider Electric EcoStruxure | Monitor and optimize energy use, from device to portfolio. | Not described on the product page. | Native BACnet, LonWorks and Modbus support. |
| Automated Logic WebCTRL | Built-in fault detection and ASHRAE Guideline 36 sequences. | Not described on the product page. | Native BACnet controllers. |
| Distech Atrius Facilities | Cloud BMS designed to enhance operations and reduce energy usage. | Not described on the product page. | Distech ECLYPSE connected controllers. |
| Aqueduct aQ EnergySmart | Electrical single line twin, peak demand, power factor and load sequencing. | Regression on use plus cooling and heating degree days, or uploaded bills. | Smart Controls over BACnet, Modbus and LoRaWAN relays. |
What measured energy management is worth
Median savings from fault detection and diagnostics; energy information systems alone reached 4%.
Source: US DOEPossible cut in US commercial building energy from well-tuned controls, in a PNNL simulation.
Source: US DOE and PNNLShare of US commercial building energy used for space heating in 2018, the largest end use.
Source: US EIAWhy teams pick Aqueduct as their BEMS
Aqueduct reads utility meters, sub-meters and bills into aQ Core, fits a weather-normalized baseline for each site and prices the gap at your tariff. The electrical twin shows which feeder or rooftop unit carries the waste.
Smart Controls then sequences loads or resets setpoints where control is enabled, with owner approval, and the next weeks of meter data show whether the saving held. Aqueduct runs on 300+ sites in 21 countries. Partners install the meters and controllers.
Sources9 references cited on this page
- Siemens, Desigo CC building management platform.
- Johnson Controls, Metasys 15.0 release, 18 November 2025.
- Honeywell, Forge Performance+ for Buildings release, 3 November 2022.
- Schneider Electric, building management system launch page.
- Automated Logic, WebCTRL building automation system.
- Acuity Brands, Distech Controls Facilities BMS software suite, 22 October 2024.
- US DOE, Smart Energy Analytics Campaign.
- Pacific Northwest National Laboratory study, 2017.
- US EIA, commercial building end uses, 2018.
Related
Common questions
BEMS software is a building energy management system: controls plus energy metering and reporting for one building or many. The term is used most in the UK and Europe. A strong BEMS shows expected against actual use and can act on the equipment, which is how Aqueduct pairs aQ EnergySmart with Smart Controls.
Yes, for anything beyond a whole-building total. A main meter shows that use rose, while sub-meters on feeders, chillers and air handlers show where. Aqueduct shows that data per feeder in its electrical digital twin. See load disaggregation for sites with few meters.
Aqueduct regresses past use against cooling and heating degree days for each site, then compares actual use with that expected value. A hot summer raises the expected figure too, so the difference reflects what the team changed. See weather-normalized baselining.
Yes, if the M&V plan accepts it. Aqueduct supplies metered data, the baseline model and a logged history of each control change, which an ESCO or reviewer can test against IPMVP or ASHRAE Guideline 14. The parties still agree the protocol. See measurement and verification.
See Aqueduct on your own facility.
Bring a site, a utility bill or a question. We will show you where the loss is.